Managers will be permitted to challenge one call in the first six innings of the game.

Managers will then be permitted to challenge up to two calls after the sixth inning.

Managers will be permitted to challenge nearly all plays except balls and strikes.

During a challenge, the play will be reviewed by officials at MLB offices in New York and their decision will be final. Those officials will have umpiring experience.

A manager will only be charged with a review if the call is upheld.

If a manager runs out of challenges, the umpires will still be permitted to ask for a review on home run calls if they deem it necessary.

The one obvious weakness that stands out is that it does not appear that managers will receive any extra challenges if a game goes into extra innings. That could ultimately impact how a manager uses his challenges late in a game.

Still, this is a huge and welcome move by Major League Baseball and one that is long overdue.